PROJECT SUMMARY/ABSTRACT We are requesting funds to purchase a Zeiss LSM 800 point-scanning confocal microscope with Airyscan detector to support NIH-funded research on the West Campus of Ohio State University. This instrument represents essential and enabling technology that will support the research of 13 PIs (8 major users and 5 minor users) with a particular strength and focus in neuroscience and neuromuscular research. These users hold 23 active grants totaling $7.1 million in annual funding, including 16 NIH research grants totaling $5.6 million and 7 research grants from NSF and private foundations totaling $1.5 million. All 8 of the major users and 3 of the minor users are NIH-funded. NIH-funded users and NIH-funded major users will account for 80% and 70% of the Available Usage Time, respectively. The instrument will replace an obsolete Leica TCS SL point-scanning confocal microscope and will provide a modern and reliable instrument offering substantial and much-needed improvements in sensitivity for imaging of fixed cells, tissues and zebrafish embryos, as well as additional laser lines, higher scan resolution, a rotatable scan area, and a motorized stage. Together, these will enable multi- wavelength imaging, image cropping and tiling capabilities not available on the current instrument. The Airyscan detector will offer greatly improved detection and image quality due to impressive additional gains in sensitivity, as well as a 1.7-fold improvement in spatial resolution. The instrument was selected after extensive research and consultation as well as on-site testing of two systems and will be housed in the Neuroscience Imaging Core, which is an established and successful core facility of the Ohio State University Neuroscience Center Core that is supported by an NIH P30 Center Core grant (Brown, PI). Importantly, this is the only confocal imaging core facility within 1.4 miles of the West Campus of Ohio State University and is thus critical for NIH-funded research on this part of campus. Established in 2004 and now in its 14th year of NIH funding, the core facility is directed by Dr. Brown who is a cell biologist with more than 25 years of experience in fluorescence microscopy. Dr. Brown supervises the Facility Manager, Ms. Monsma, who manages all day-to-day operations, including training, user support, scheduling and equipment maintenance. Ms. Monsma has an MS in cell biology and extensive experience in confocal microscopy including first-author publications and 13 years of experience managing this facility. The NIH P30 Center Core grant was recently funded for another 4 years and provides salary support for Ms. Monsma, as well as the confocal service contract. An established user fee structure, billing mechanism and financial backing from the College of Medicine guarantee continued sustainable operation when the P30 ends. Thus, this proposal leverages substantial institutional support, established expertise and resources to acquire a modern instrument that will support the aims of a large number of NIH-funded researchers and projects.